Approximately 30% of psychiatric inpatients have a depressive syndrome with a delusion. A review of the literature and the results of a pilot study convinced the investigators that tricyclic antidepressants are ineffective in treating this group of depressives. Most clinicians prefer not to use electroconvulsive therapy as an initial treatment for these patients. Consequently, this leaves the clinician the choice between either an antipsychotic alone or an antipsychotic plus an antidepressant. There have been no studies evaluating the relative and absolute efficacy of these treatments. Thus clinicians are treating patients with drug regimens which have not been proven effective. The first objective of this project is to compare the response of delusional depressives treated with either perphenazine alone or with a combination of perphenazine plus amitriptyline. The second objective is to measure the plasma levels of amitriptyline, perphenazine, and their active metabolites. It is hoped that this will explain why some patients respond to treatment and others fail to respond.